Severe drought continues in Southwest
By Summit VoiceFRISCO — Snowpack across the West is still somewhat of mixed bag in this no-Niño winter, but February storms did help bolster water supplies across the northern tier of states, according to the monthly update from USDA’s Natural Resources Conservation Service.
East of the Continental Divide as well as parts of Washington, northern Oregon, northern Idaho and western Montana are now forecast to have near-normal or above normal water supplies, according to the forecast from the NRCS National Water and Climate Center.
Snowpack in southern and eastern Oregon, California, Arizona, New Mexico and Nevada is still far below normal. Although time is running out for snowpack recovery in drier areas, NWCC hydrologist Cara McCarthy said she won’t rule it out.
“We might have another miracle March,” she said, referring to late-season snowfall that has occurred in previous years. “During February we saw a dramatic recovery in the western Cascades of Washington.”
Some snow telemetry, or SNOTEL, sites in the eastern parts of Montana, Wyoming and Colorado received three times the normal amount of precipitation. The center will continue to monitor and forecast water supplies for the next three months.
“We’ll be keeping an eye out for potential stream flooding in those areas,” McCarthy said.
Lake Powell reservoir, which provides water to parts of Nevada, Arizona and California, is now forecast to receive 109 percent of normal streamflow, up 15 percent from last month.
NRCS’ streamflow forecasts are one of the tools used to predict drought. In states where snowmelt accounts for the majority of seasonal water supply, information about snowpack is a key indicator of future water supply.
Streamflow in the West consists largely of accumulated mountain snow that melts and flows into streams as temperatures warm into spring and summer. NRCS scientists analyze the snowpack, air temperature, soil moisture and other measurements taken from remote sites to develop the water supply forecasts.
The NRCS has conducted snow surveys and issued regular water supply forecasts since 1939. Since the late 1970s, NRCS has been installing, operating and maintaining an extensive, high-elevation automated system called SNOTEL, designed to collect snowpack and related climatic data in the western U.S. and Alaska.